OPTICAL CHARACTERISTICS INVESTIGATION ON COMPOUND SEMICONDUCTOR NATIVE DEFECTS AND RELATED MATERIALS

研究了半绝缘砷化镓、红外发光材料和掺Er石英玻璃光纤等材料的发光和光吸收特性。研究表明，半绝缘砷化镓中的本征缺陷可以用恢复特性、漂白和吸收特性来表征。这些类型的表征程序正在扩展，以检查二维空间分布特征。这项研究工作还在继续。对稀土激活的红外发光材料进行了系统的研究。结果表明，具有氟化物晶格的Er激活的荧光粉在2.6~2.8 nm波长范围内具有较强的发光。结果表明，这些荧光粉与GaAs：Si红外发光二极管和PbS光导探测器相结合，是一种简单方便的大气水汽传感器检测装置。探索长波长发光材料的研究活动仍在继续。已经对掺Er石英玻璃光纤的放大自发辐射特性进行了实验。用Ar离子激光器作为激发源进行了测量。已有研究表明，高能级的波长转换过程并不完全是先前假设的非辐射衰减过程，而是相当大程度上是由于中间的辐射衰减过程。

Investigations have been carried out for luminescence as well as optical absorption characteristics of several interesting materials including semi-insulating GaAs, infrared emitting phosphors and Er-doped silica glass fiber.It has been previously demonstrated that the native defects in semi-insulating GaAs can be characterized by recovery characteristics as well as bleaching and absorption characteristics. These kinds of characterizing procedures are being extended for examining two dimensional, spatial distribution characteristics. This research work is being continued.Systematic investigations on rare earth-activated, infrared emitting phosphors have been carried out. It has been shown that Er-activated phosphors having flouride lattices present fairly intense luminescence at 2.6 to 2.8um wavelength region. It has been demonstrated that these phosphors present simple and convenient detecting device for atmospheric water vapor sensor, if combined with GaAs:Si infrared light emitting diode and PbS photoconductive detector. Research activity is still continued for exploring longer wavelength emitting light materials.Examinations have been performed on amplified spontaneous emission characteristics in Er-doped, silica glass fiber. The measurements were carried out by using Ar ion laser as excitation source. It has been fairly established that the wavelength conversion processes from higher levels are not solely nonradiative decay process as previously postulated but considerably due to intermediate radiative decay process.